There is now a huge amount of movement in the area of what we have called “Diverse” Platform as a Service i.e. PaaS that delivers a number of different application infrastructure technologies on a mix-and-match basis and where there is no proprietary technology layer at any point in the platform stack. Amongst these we would include OpenShift, Cumulogic and CloudFoundry from our recent set of posts. AppFog sits in this category, and the fact that it has been recently renamed from PHPFog highlights a major trend in the space, the vendors typically start by developing a single technology, build an initial business plan and gain some market traction within that niche, and then move on to supporting a broader range of platforms.
So, it is important when assessing these vendors to differentiate between the short-term tactical choices they have made for their initial go-to-market, and their ability to deliver a longer-term vision based on their fuding, their people and their architecture. This even applies to the larger players entering the space – VMware, Red Hat, because at this point, all of these platforms are work in progress.
AppFog has positioned itself as a PaaS for PHP developers, and invested on the basis that the vast majority of websites run PHP so this is in fact the volume market. They claim around 20,000 current users. Whilst we agree there is a large potential PaaS PHP market, we do want to raise two notes of caution
- The vast majority of websites that run PHP, certainly the new ones, use a pre-built blogging or content management technology (such as WordPress), and there isn’t a lot of additional value that a PaaS brings to the party for the simple WordPress use cases – certainly not enough to justify a significant premium over the standard approach on a hosted Virtual Server, which is becoming extremely cheap now for the volume market.
- Many people who use PHP (including me) will be used to editing code in-situ on the server using a command-line editor, and this isn’t a PaaS activity – you need access to the infrastructure layer.
So, within the PHP community, Appfog are looking for a sub-community of developers who are building PHP sites or customizing them (for example by modifying WordPress Plugins or Themes), and are prepared to move to a more structured deployment model. Appfog delivers this by using Git – an up-and-coming Open Source Software Configuration Management System – like Subversion or CVS.
Because PHP is scripted and the Apache web server directly executes the source files, Git can be used to incrementally deploy software onto a server (rather than the problem of packing/unpacking and incrementally uploading a WAR file that exists with Java applications) . Generally this isn’t done from an IDE (like Eclipse) as you would expect in a Java environment, but from a script.
Under the covers AppFog are using the open source CloudFoundry codebase from VMware, and then an underlying IaaS layer. Because AppFog build on CloudFoundy they don’t have their own APIs, but do make use of VMware APIs that we are suggesting should become standards.
The big AppFog differentiator is the developer-focussed ease of use layer they have put on top which is designed to provide a low-hassle on-ramp for developers onto a free limited-scalability shared tenancy product and then drive developers to pay $30 per month to get a single-tenancy PaaS and get rid of all the hassles of setting up a virtual server somewhere and installing PHP on it and Apache and DNS and whatever.
Once the developers are on AppFog the theory is they won’t leave if they need to scale up beyond that and add additional services. Appfog has a tiered pricing model to support this. Over time they will add additional languages and platforms to broaden the addressable market for the offering.
At this stage at the Virtualization Practice we’re not installing and testing PHP code on PaaS, so it’s hard to perform the level of detail in our comparison that we perform with our Groovy/Grails/Spring evaluations. However, it does seem that AppFog are addressing the major issue we had with Red Hat’s OpenShift – the fragmentation of user interface resulting from the separation of the development environment, the PaaS management and the IaaS management. There is a single billing point – you don’t sign up to the PaaS separately from the IaaS, and the use of developer-centric SCM technology to deploy means there isn’t a separate PaaS management web interface.
Given the limited adoption of PHP in the Enterprise, AppFog will likely surface for Enterprise customers in a year or so when their cross-language support matures. However, given that the Virtualization Practice itself is WordPress with major customizations we ourselves are in the target market, so we will be continuing to track it.